[postgis-devel] Postgis 3.1 minimum requirements update

[Greg Troxel]

rmrodriguez at carto.com writes:

> Hi all,
>
> I want to follow tradition an increase the minimum requirements for
> Postgis 3.1 dependencies:

I don't think it's a good thing to increase requirements just for the
sake of increasing them.  So I object to the notion that having a
tradition of increases is a good thing.

Keep in mind that people who participate in development almost always
have the latest installed for all these sorts of things.  Users do not;
they have what their packaging system provides.  I view LTS as not
relevant for new postgis (after all the LTS should have old postgis,
presumably what LTS people want), but I think it's important to look to
packaging systems/distributions that people run to see what the
situation is.

Each increase means that there are systems (packaging systems,
individual systems) where postgis would have built and then doesn't, and
that's of course bad.  There needs to be some benefit, such as in terms
of increased performance (for those building with a newer version, vs
the same build without the deprecation).  Another benefit could be
better semantics, and another could be getting to remove significant
amounts of compat code.

> Minimum PG version: 9.6 (was 9.5)

(README.postgis does not seem to address this; probably it should.)

That doesn't bother me personally.  As a data point, pkgsrc still has
9.4 and 9.5, but also 9.6, 10, 11, 12.  That's a clue that people with
databases tend to update slowly.  I don't know what people who have
postgis in production think.

What's the gain of changing this, to offset the pain caused by people
using 9.5?

> Recommended GEOS version: 3.8 (was 3.7)

'Recommended" in a vacuum is odd, because the standard approach is to
run the most recent release from a given project, eccept that after big
changes it is sensible to hold off 3-6 months.  And, releases that
withdraw APIs have a much longer time before they can be considered
generally recommended (e.g. proj).

So I don't see postgis labeling something 'recommended' as all that
helpful.  If there is a statement that 3.8 works better than 3.7 for
some specific postgis reason, or some new functions are available, then
by all means tell it like it is, but I don't see that that needs
discussion as there are unlikely to be disagreements.

Currently there's a statement about increased functionality with 3.7.

> There was some discussion about also upping the requirements for GDAL
> or PROJ in the past, so I think now is a good time to discuss it too
> in case any want wants to bring it to the table.

I'll treat that as a "if anyone wants to send a note on either topic
that explains where we are, what we might change to, and the pros and
cons" inviation only :-)